1. Field of the Invention
The invention relates to a mechanical device for blocking flexible strands, such as laces, cords, cables, ropes, strings, or any other such product or filiform element.
More specifically, the invention relates to the blocking of laces of articles of footwear as such articles of footwear are tightened by means of the laces. Thus, the invention also relates to an article of footwear equipped with a blocking device, and to a lace tightening mechanism provided with a blocking device.
More specifically, the invention relates to the field of sports and especially to footwear for snowsurfing or snowboarding, skiing, cross country skiing, roller or ice skating, cycling, hiking, walking, or the like, as well as to tightening mechanisms for bindings and products such as backpacks, including such strands in association with the tightening and/or the compression of these products or of parts thereof.
2. Description of Background and Relevant Information
It is known to block flexible strands, such as the laces of articles of footwear, by means of a blocking device.
For instance, French Patent Publication No. 2 706 743 and U.S. Pat. No. 5,477,593 disclose a blocking device that acts at least on one strand, such as at least one strand of a lace. According to these documents, the device includes a pushing device that defines the rotational axis of a blocking member, as well as a hollow body, one cavity of which defines at least one pathway for the passage of each strand, on the one hand, and a housing for the blocking member, on the other hand. The latter has a circular shape and is free in rotation about the axle that is itself movable in translation.
The device according to FR 2 708 743 and U.S. Pat. No. 5,477,593 functions by cooperation of the blocking member with each pathway for the blocking of each strand through a wedging effect. The blocking member is elastically biased in the direction for blocking the strand(s) by acting on its rotational axis. The elastic bias prevents an ill-timed unblocking.
In this manner, although it is elastically biased, the blocking member remains free in rotation and allows balancing the tensions on the two strands, even when there is a difference between the forces exerted on the strands. The blocking is therefore still achieved.
The reverse operation, that of unblocking, is obtained by manual action on the pusher against the elastic bias. The unblocking remains effective as long as the manual action is sustained. If the manual action is stopped, the elastic bias then puts the device back into a blocking condition. Consequently, it is necessary to sustain the manual action during the entire time the strand passes through during the unblocking. This can be tedious inasmuch as, in general, one has to act on the device with one hand, and simultaneously act on the strand with the other hand, especially if the length of the strand to be freed is substantial, for example when one wishes to entirely open a shoe to remove it.
In order to simplify the unblocking operation, especially to avoid having to sustain a manual unblocking action, a device that is not provided with an elastic mechanism can be used.
For instance, U.S. Pat. No. 4,807,333 provides for a blocking device that acts on at least one strand. The device includes a rotational axis for a blocking member and a hollow body, one cavity of which defines at least one pathway for the passage of each strand, on the one hand, and a housing for the blocking member, on the other hand. The blocking member has a circular shape and is free in rotation about an axis that is itself movable in a plans substantially parallel to the blocking member. The device functions by cooperation of the blocking member with each pathway for the blocking of each strand through a wedging effect. A control member allows biasing the rotational axis of the blocking member for movement towards a direction for blocking or unblocking the strand(s).
Thus, according to U.S. Pat. No. 4,807,333, it is sufficient to momentarily act on the control member to place the device in an unblocking condition. It is not necessary to act simultaneously on the device with one hand and on the strand with the other hand.
However, it has been recognized, when the device is being used according to U.S. Pat. No. 4,807,333, that the blocking member sometimes recovers a blocking position without being biased by an action on the control member. The manipulations of the device sometimes result in an undesired blocking. For example, the blocking member can be biased into a blocking direction by gravity, or friction of the strand(s) on the blocking member can sometimes drive it in a blocking position. In other words, the blocking member does not stably remain in a blocking position. Conversely, the blocking member does not remain in the blocking position due to the lack of elastic bias.